diff options
Diffstat (limited to 'src/math/ilogb.c')
| -rw-r--r-- | src/math/ilogb.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/src/math/ilogb.c b/src/math/ilogb.c index 5a1819d8..64d40154 100644 --- a/src/math/ilogb.c +++ b/src/math/ilogb.c @@ -3,22 +3,24 @@ int ilogb(double x) { - union dshape u = {x}; - int e = u.bits>>52 & 0x7ff; + #pragma STDC FENV_ACCESS ON + union {double f; uint64_t i;} u = {x}; + uint64_t i = u.i; + int e = i>>52 & 0x7ff; if (!e) { - u.bits <<= 12; - if (u.bits == 0) { + i <<= 12; + if (i == 0) { FORCE_EVAL(0/0.0f); return FP_ILOGB0; } /* subnormal x */ - for (e = -0x3ff; u.bits < (uint64_t)1<<63; e--, u.bits<<=1); + for (e = -0x3ff; i>>63 == 0; e--, i<<=1); return e; } if (e == 0x7ff) { FORCE_EVAL(0/0.0f); - return u.bits<<12 ? FP_ILOGBNAN : INT_MAX; + return i<<12 ? FP_ILOGBNAN : INT_MAX; } return e - 0x3ff; } |